Numerous antibiotics in the prior art, which exhibit activity against a broad spectrum of Gram-positive bacteria, have been produced from species of microorganisms which have been isolated from soil samples throughout the world. Such antibiotics continue to be in demand.
The new compounds of the present invention have been named tiacumicin. They are believed to be of the following chemical structure I ##STR1##
wherein R is a substituent of the formula ##STR2##
wherein each R.sub.3 is a hydrogen or a C.sub.1 to C.sub.4 fatty acid;
wherein R.sub.1 is hydrogen or hydroxy; and wherein R.sub.2 is hydrogen or a substituent of the formula ##STR3##
wherein one R.sub.4 is hydrogen and the other is a substituent of the formula ##STR4##
Preferred compounds of the present invention include compounds which have been named tiacumicin A through F. Tiacumicin A is the compound of formula I wherein R is the following substituent ##STR5##
and R.sub.2 and R.sub.3 are hydrogen.
Tiacumicin B is the compound of formula I where R is the following substituent ##STR6## R.sub.1 is hydroxy; and R.sub.2 is a substituent of the formula ##STR7##
Tiacumicin C is the compound of formula I where R is a substituent of the following formula ##STR8## R.sub.1 is hydroxy; and R.sub.2 is a substituent of the following formula ##STR9##
Tiacumicin D is a compound of formula I where R is a substituent of the following formula ##STR10## R.sub.1 is hydroxy; and R.sub.2 is a substituent of the following formula: ##STR11##
Tiacumicin E is a compound of formula I where R is a substituent of the following formula: ##STR12## R.sub.1 is hydroxy; and R.sub.2 is a substituent of the formula: ##STR13##
Finally, Tiacumicin F is a compound of formula I wherein R is a substituent of the following formula: ##STR14## R.sub.1 is hydroxy; and R.sub.2 is a substituent of the formula: ##STR15##